Ureter
The ureter is a paired fibromuscular tube that conveys urine from the kidneys in the abdomen to the bladder in the pelvis.
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Gross anatomy
The ureter is 25-30 cm long and has three parts:
- abdominal ureter: from the renal pelvis to the pelvic brim
- pelvic ureter: from the pelvic brim to the bladder
- intravesical or intramural ureter: within the bladder wall
Course
The ureter begins its descent to the bladder by running along the medial aspect of the psoas muscle. Here, the ureter lies anteriorly and slightly medial to the tips of the L2-L5 transverse processes.
It enters the pelvis anteriorly to the sacroiliac joint at the bifurcation of the common iliac vessels (at the pelvic brim) and then courses anteriorly to the internal iliac artery down the lateral pelvic sidewall.
At the level of the ischial spine it turns forward and medially to enter the posterolateral wall of the bladder, where it runs an oblique 1-2 cm course, before opening into the bladder at the internal ureteric orifice 1,2.
Relations
The relations of the ureter are somewhat complex due to the differences between the left and right sides of the abdominal cavity and differences between male and female pelvic viscera.
Abdominal ureter
Following the course of the ureter from superior to inferior 1,2:
- posteriorly: psoas muscle; genitofemoral nerve; common iliac vessels; tips of L2-L5 transverse processes
- anteriorly
- right ureter: descending duodenum (D2); gonadal vessels; right colic vessels; ileocolic vessels
- left ureter: gonadal artery; left colic artery; loops of jejunum; sigmoid mesentery and colon
- medially
- right ureter: IVC
- left ureter: abdominal aorta, inferior mesenteric vein
Pelvic ureter
- posteriorly: sacroiliac joint, internal iliac artery
- inferiorly
- male: seminal vesicle
- female: lateral fornix of the vagina
- anteriorly
- male: ductus deferens
- female: uterine artery (in the broad ligament)
- medially
- female: cervix
It should be noted that the only structures to anteriorly pass over the pelvic ureter is the ductus deferens in males and the uterine artery in females.
Constrictions
The ureter has a diameter of 3 mm 1 but there are three constrictions, which are the most common sites of renal calculus obstruction:
- at the pelviureteric junction (PUJ) of the renal pelvis and the ureter
- as the ureter enters the pelvis and crosses over the common iliac artery bifurcation
- at the vesicoureteric junction (VUJ) as the ureter obliquely enters the bladder wall
Blood supply
- arterial supply: from branches of the renal artery, abdominal aorta, superior and inferior vesical arteries
- some texts also include supply from the gonadal, middle rectal and uterine arteries 1,2
- venous drainage: via similarly named veins but is highly variable 1,2
Lymphatic drainage
- abdominal ureter: aorto-caval and common iliac nodes
- pelvic ureter: internal and external iliac nodes 1
Innervation
- derived from renal, aortic and hypogastric autonomic plexuses 1
Histology
The ureteric wall is composed of three layers (from outside to inside):
- adventitia
- smooth muscle
- transitional cell epithelium 1
Variant anatomy
Related pathology
Related Radiopaedia articles
Anatomy: Abdominopelvic
- skeleton of the abdomen and pelvis
- muscles of the abdomen and pelvis
- spaces of the abdomen and pelvis
- anterior abdominal wall
- posterior abdominal wall
- abdominal cavity
- pelvic cavity
- perineum
- abdominal and pelvic viscera
- gastrointestinal tract
- spleen
- hepatobiliary system
-
endocrine system
-
adrenal gland
- adrenal vessels
- chromaffin cells
- variants
- pancreas
- organs of Zuckerkandl
-
adrenal gland
-
urinary system
-
kidney
- renal pelvis
- renal sinus
- avascular plane of Brodel
-
variants
- number
- fusion
- location
- shape
- ureter
- urinary bladder
- urethra
- embryology
-
kidney
- male reproductive system
-
female reproductive system
- vulva
- vagina
- uterus
- adnexa
- Fallopian tubes
- ovaries
- broad ligament (mnemonic)
- variant anatomy
- embryology
- blood supply of the abdomen and pelvis
- arteries
-
abdominal aorta
- inferior phrenic artery
- celiac artery
- superior mesenteric artery
- middle suprarenal artery
- renal artery (variant anatomy)
- gonadal artery (ovarian artery | testicular artery)
- inferior mesenteric artery
- lumbar arteries
- median sacral artery
-
common iliac artery
- external iliac artery
-
internal iliac artery (mnemonic)
- anterior division
- posterior division (mnemonic)
- variant anatomy
-
abdominal aorta
- portal venous system
- veins
- anastomoses
- arterioarterial anastomoses
- portal-systemic venous collateral pathways
- watershed areas
- arteries
- lymphatics
- innervation of the abdomen and pelvis
- lumbar plexus
-
sacral plexus
- lumbosacral trunk
- sciatic nerve
- superior gluteal nerve
- inferior gluteal nerve
- nerve to piriformis
- perforating cutaneous nerve
- posterior femoral cutaneous nerve
- parasympathetic pelvic splanchnic nerves
- pudendal nerve
- nerve to quadratus femoris and inferior gemellus muscles
- nerve to internal obturator and superior gemellus muscles